Vacuum cleaner



April A25, 1939.

G. E. LOFGREN VACUUM CLEANER Filed March 12, 1955 3 Sheets-Sheet 1 '/02lNvE TOR,

ATTORNEY.

April 25, 1939. G. E. LOFGREN VACUUM CLEANER Filed March l2, 1955 3SheetS--Sheetl 2 April25, 1939. f G ELQFGRE 2,155,669

VACUUM CLEANER Filed March l2, l1935 3 Sheets-Sheet 3 A? aIyENTOR, BY b6.5 ATTORNEY.

Patented Apr. 2,5, 1939 UNITED STATES' VACUUM CLEANER Gustaf EinarLofgren, Riverside, Conn., assignor to Electrolux Corporation, Dover,Del., a corporation of Delaware Application March 12, 1935, Serial No.10,620

12 Claims.

My invention relates to vacuum cleaners and more particularly to vacuumcleaners of the enclosed bag type.

One of the objects of my invention is to provide a vacuumcleaner of thistype in which the bag may be more readily removed for emptying than hasbeen the case heretofore. In the past, cleaners of this type having acasing adapted to be supported horizontally upon a horizontal surfacehave been formed with an opening in a vertical plane through which thebag is removed. The open mouth of the bag is secured in this opening,and in order to remove the bag when partially filled with dirt, it hasbeen convenient to stand the cleaner on end in order that the dirt willnot fall out when the cleaner is opened. In order to render thisunnecessary, the cleaner in accordance with the present invention isformed with an opening for withdrawal of the dust bag located in aninclined plane. Thus, the advantages of a horizontal construction areretained, and itis also convenient to remove the bag without firststanding the cleaner on end. i

The inclined dust bag opening has a further advantage. It has heretoforebeen proposed to employ a dust bag which is longer than the availablespace within the cleaner casing in which it is received. Such a bag has,of course, a greater wall surface than one of equal or shorter lengththan the space, and consequently offersy less resistance to the passageof air. Necessarily, the walls of the bag arefolded in order that it maybe received in the smaller space and difficulties have been experiencedin properly inserting the bag due to the fact that most of the folds areapt to occur adjacent to the mouth of the bag and hence tend to blockthe passage of dust ladened air into the bag. Even if the fan isoperating during insertion of the bag, and hence producing a suctioneffect tending to draw the bag into the space, this tendency will cease-as soon as the closedend of the bag strikes the end of the space.Thereafter, the suction simply tends to expand the bag and. presses thefolds, which are formed adjacent to the open en`d of the bag by theopersides of the space. I have determined, however,

that if the mouth of the bag is held in a position 6 inclined withrespect to the lengthwise extent of the space, as it' is in a cleaner inaccordance with the present invention due to the inclination of the dustbag opening, the tendency of the air flow to expand the baghas theeffect of preventing the formation of folds adjacent to the mouth atorforcing this end into the space, against the.

of the bag, where the axis of the bag curves from an inclined to ahorizontal position, and causes the folds to be distributed more towardsthe closed end of the bag. Consequently, the inclined opening aids inthe proper insertion of the long bag.

v.Another object of the invention is to reduce 5 lthe noise produced bythe air discharged from the cleaner. To accomplish this, I cause the airto pass through a comparatively long passage after leaving the fan andto be discharged to the atmosphere through a plurality of openl0 ings,rather than through a'single opening. Thus the noise of the fan isdeadened before the airis discharged from the cleaner and the roarproduced by the rapid flow of air through a single opening is greatlyreduced. 15

It is desirable that vacuum cleaners should be available for blowingpurposes, as well as for their normal use as suction cleaners, and oneof the objects of my invention is to provide connections for a hose forboth blowing and suction purposes at the same end of the vacuum cleaner.

A further object of my invention is the provision of a casing for avacuum cleaner, particu- -larly of the enclosed bagtype, including twostampings, preferably an upper and a lower one. Heretofore, casings forvacuum cleaners of this type have been cylindrical with an opening ateither end, thus necessitating detachment andA removal of the interiorparts if access to them becomes necessary for purposes of repair'or soforth. A two-piece casing, on the other hand, makes it possible tosecure the interior parts to either of the stampings, and thus accessthereto is possible by merely removing the other stamping. I'he originalassembly of the device is also facilitated inasmuch as the interiorparts may be secured to one stamping before the other stamping issecured in place.

A casing made in this manner has many other advantages, some of the moreimportant of which will be mentioned. In the event of injury to onepiece, only that piece need be replaced, thus reducing the cost ofrepairs. In this connection also, if the interior parts are secured tothe undamaged stamping, the injured stamping may be replaced withoutdisturbing them. 'I'his will usually be the case if the interior partsare secured to the lower stamping, as shown in this application,inasmuch as the upper stamping is the one more aptfto be injured. With acasing comprising two stampings, one or both ends of the casing may beintegral with these stampings, rather than separate pieces, as isnecessary with a cylindrical casing, thus making a cheaper constructionwhile eliminating opportunities for leaks. Stampings may be of most anydesired shape, thus making possible a wide latitude in the design of thecasing so that it may best serve its intended purposes. For instance,reinforcing ribs may be stamped directly in the casing. Also, the jointbetween the two stampings may be made air-tight, without soldering orriveting, by the use of a strip of packing material, such as rubber. Thesuction produced within the casing exerts a large force tending to drawthe abutting edges of the stampings together, and thus effects a tightseal, regardless of whatever other means are employed to fasten theparts together. Other advantages of this type of casing will be apparentfrom description contained hereinafter.

Another object of my invention is to provide means whereby the pluralityof outlet openings above referred to are closed when a hose is attachedto the blowing opening, this means also serving to close the hoseconnection blowing opening when no hose is connected.

Further objects and advantages of my invention will be apparent from thefollowing description taken in connection with the accompanying drawingsforming a part of this specification and of which:

Fig. 1 is a. side view of a vacuum cleaner in acv cordance with myinvention;

Fig. 2 is a front view of the device shown in Fig, 1;

1 Fig. 3 is a rear view of the device shown in Fig.

Fig. 4 is a cross-sectional view taken on the line 4--4 of Fig. 1;

Fig. 5 is a cross-sectional view taken on the line 5-5 of Fig. 2;

Fig. 6 is a cross-sectional view taken on the line 5-,6 f Fig. 5;

Fig. 'I is a cross-sectional view taken on the line 1-1 of Fig. 5;

Fig. 8 is a cross-sectional view on an enlarged scale taken on the line8 8 of Fig. 7;

Fig. 9`is a cross-sectional view on a similar scale taken on the line 99 of Fig. '1;

Fig. 10 is a cross-sectional view of a portion of the cleaner as shownin Fig. 5, but with a hose connected in position for blowing;

Fig. 11 is a perspective view of a part of the vacuum cleaner shown inthe preceding figures;

Fig. 12 is a cross-sectional view on an enlarged scale showing the dustindicator;

Fig. 13 is a cross-sectional view taken on the line I3I3 of Fig. 12; and

Fig. 14 is a cross-sectional view taken on the line I4I4 of Fig. 13.

Referring to the drawings, reference character I designates generally ahollow casing made of metal or other rigid sheet material. Casing IIIcomprises anupper part or shell II and a lower part or shell I2. If, thecasing is made of sheet metal the parts are preferably formed bystampmg.

Lower part I2 is clearly shown in Fig. l1. Secured within part I2, as byWelding, riveting or the like, is a U-shaped channel member I3, whichserves as a motor support. The upper horizontal edge of part I2 isformed with a V-shaped groove I4 adapted to receive a bead I5 of rubberor other resilient material. Bead I is formed with a dove-tailed portionI6, (Fig. 6) and the lower horizontal edge of upper part I I is stampedto form an edge I1 which extends into the upper groove formed by thedovetail. Bead I5 serves the dual purpose of providing an air-tight sealbetween the upper and lower parts and of providing a bumper or guardaround the cleaner casing to prevent the marring of furniture with whichthe casing accidentally may come in contact. Upper part II of the casingis secured to channel member I3 by means of a plurality of screws or thelike I9, and is 4thus held rigidly with respect to the lower part I2.

The forward part of the casing comprises a casting I9 into which aresecured, as by screws 23, the forward ends of both the upper and lowerparts II and I2, respectively. Casting I9 is formed with a largecircular opening 29 located in an inclined plane, as is clearly shownparticularly n Figs. 5 and 12. A cylindrical wall 2| (Fig. 7) extendsrearwardly from the opening 2D to the rear of casting I9. 'I'he castingis formed with an intermediate transverse wall 22, which extends acrossthe entire casting below the opening 20. A cylindrical inner casing 25is positioned within casing I9, and is joined to the rear end ofcylindrical part 2l of casting I9. Cylindrical part 2I and inner casing25 provide a space within which is positioned a dust bag 25. The lengthof bag 26 is preferably somewhat greater than the space into which it isinserted, so as to obtain the benets of an increased wall surface. Whenin place, the walls of the dust bag are folded, as shown in Fig. 5. Acage 21 made of wire mesh or perforated plate may be located withininner casing 25 in order to space the dust bag from the casing. Thisaids the passage of air through the walls of the dust bag. The forwardopen end of the dust bag is secured to a ring 28 having an outwardlyextending flange 29 (Fig. 12). A packing ring 39 is secured over theedge of flange 29 and the flange and packing ring are adapted to beclamped between the forward face of casting I9 anda cover member 3|,which is secured in place by two or more spring clips 32. Cover member3| is formed with a threaded central opening 35 which is adapted toreceive the threaded end of a hose 39.v

Channel member I3 is provided with a plurality of inwardly extendinglugs 31, which are preferably made of a phenol condensation product orother electric insulating material. An electric motor 39 is'supportedfrom lugs 31 by means of pins 39 extending through holes in the lugs 31and in lugs 40 formed on the motor. Pins 39 may be surrounded with coilsprings in order to give the motor a resilient mounting.-

Secured to the shaft of motor 39 are one or more fan rotors 4I. Theserotors are surrounded by a fan housing 42, which has a cylindricalportion secured to a flange 45 formed on the motor. Flange 45 carries anannular sealing ring 45 of resilient material, which also engages therear end of cylindrical inner casing 25. Sealing ring 46 effects anair-tight seal between the motor and casing 25, while permitting aslight amount of movement between these parts.

Motor 38 is formed with openings 41 in the forward bearing plate, andall of the air discharged from fan rotors 4I is forced to pass throughthese openings. The rear part of the motor is formed with a singleopening 49, to which is secured a conduit' member 49, which maypreferably be made of rubber or other flexible material. The shape ofmember 49 may best be seen from Figs. 5 and 6. The lower rectangularvend 50 of member I49 receives a rectangular piece 51 and an innerconvex top 68. A strip of asbestos or other heat-resisting flexiblematerial 59 is preferably placed between the top 58 and inner casing 25.The portion of lower part I2 of the casing which forms the bottom 55 ofchannel 52y is preferably corrugated and is shown in Figs. 4 and 411 inorder to provide a maximum heat transfer surface and to stiffen theplate. The forward end of channel 52 communicates with a space 60 (Fig.5) formed in the casting |9 between the bottom of the casting andtransverse wall 22. Casting I9 is formed with a forward threadedaperture 6| which also communicates with the space 60. Aperture 6| isadapted to receive a threaded end of hose 36 when it is desired to usethe device for blowing purposes. Wall 22 is formed with openings 62adjacent either end thereof, which openings communicate with a space 65bounded by wall 22, circular part 2| and the outer wall of the casting.A valve member 66 is pivoted at 61 and serves to close either openings62 on the one hand or opening 6| on the other. A spring 68 serves tonormally hold valve member 66 in the position shown in Figs. '1, 8 and9, so that the central part 69 of the valve member bears against thematerial of casting I9 surrounding opening 6 I, and thus serves to closethe opening.

The hose 36 is provided with an extension 10, which, when the hose isscrewed i'nto opening 6i presses valve member 66 to the position shownin Fig. 10. In this position the end portions 1| of the valve memberbear against the lower side of wall 22 around the openings 62, and theseopenings are thereby closed. It will be seen that the end portions 1|,ofthe valve member lie in the same plane, while the central portion 69 isin a plane parallel theretobut spaced somewhat therefrom.

-Space communicates with a similar space 12 bounded by casing III, innercasing 25 and member 56. Upper part II of the casing is formed with aplurality of louver openings 15, which establishcommunication betweenspace 12 and the atmosphere. shown in Fig. 1, so as to direc-t airdischarged therethrough upwardly and away from the surface supportingthe cleaner.

The dust indicator is located in a recess formed in the upper part ofcasting I9. The indicator includes a cap-shaped member 11 sec-ured inplace within the recess by means of a member 18 having openings 19therethrough which communicate with the space immediately outside ofdust bag 26. The upper end of member 11 is formed with an annular flangewhich receives and holds in place a piece of glass or other transparentair-irnpervious material 80. A visual indicating member 8| is pivoted at82 to the bottom of the cap-shaped member 11. Member 8| comprises anarcuate portion 8'5 adapted to be rotated underneath an opening 86formed in the casting I9 above the glass 80. The upper convex surface ofpart bears markings of a nature to indicate its position. A weight 81 issecured to indicator member 8| and tends to cause the member to rotatein a clockwise direction, as viewed in Fig. 12, about pivot 82. Securedbetween the bottom of Ycap-shaped memberA 11 and member 18 is a flexiblediaphragm 88 tothe central part of which is secured a plate 89 and aflanged disc 90. -A rivet or the like 9| passes through disc 90,diaphragm 88 and plate 89, and bears aaginst a horizontal portion-92 ofindicator member 8|. A spring 95 is retained between member 18 andOpenings 65 are inclined ask dust bag ring 28 is formed with one or moredepressed portions 98 which extend into groove 91 and are provided withopenings 99, which establish communication between the space within cap3| and groove 91. Inasmuch as the space Within cap 3| is directly incommunication with the interior of dust bag 26, the pressure existingwithin the dust bag is communicated through openings 99, groove 91 andpassage 96 to within recess 16. Cap-shaped member 11 is formed with oneor more openings |00 whereby this pressure is communicated to within thecap-shaped member, and acts upon the upper side of diaphragm 98.

The bottom of part I2 of the casing and the bottom of casting |9 areformed with downwardly extending portions |0| and runners |02 aresecured to the lower ends of portions I 0|.

rIfhese runners serve to support the cleaner on the l ycasing may berounded, as shown at |08 in Fig.

l, and formed with a vertical iin |09 from which extends the electricconductor lead ||0.

The operation of the above described device is as follows:

If the hose 36 is connected to suction opening 35, as shown in Figs. l,2 and 5, and the motorfan unit is operated, air will be drawnY inthrough the hose and into the interior of dust bag 26. If a nozzle orlike cleaning implement II2 is secured to the end of hose 36 and passedover a dusty surface, dust will be drawn in with this air and depositedwithin the dust bag. The air will pass through the material of the dustbag into the inlet of the fan and be discharged from the fan and passthrough the electric motor 38, thereby cooling the motor. The air isdischarged through opening 48 at the rear of the motor and passesthrough members' 49 and 5| to within Ichannel 52. From here the airpasses into space 60 formed in casting I9 and through openings 62 inwall' 22 into space 65. Unless the hose is screwed into opening 6|,valve member 66 closes this opening and no air escapes therethrough.From space 65the air passes into space 12 formed between casing I0 andinner casing 25. From here the air is discharged through louver openings16 in a plurality of streams to the atmosphere.

It will thus be seen that the air has passed the entire length of thecleaner after having been discharged from the motor-fan unit, and thenhas its direction reversed and starts to pass to'- ward the rear of thecleaner before its passage to the atmosphere. This vcomparatively longpath oftravel of the air causes the sound produced by the operation ofthe motor-fan unit, which sound This results in a much quieter operationof the cleaner than would be the case if the air were immediatelydischarged after having passed through the motor-fan unit. Thecorrugations in the bottom of channel 52 permit radiation of heat fromthe air which has been warmed by the motor, and thus prevent anypossibility of overheating of the cleaner.

If it is desired to use the device for blowing purposes, hose 36 isscrewed into opening 6|. The extension 10 on the hose presses valvemember 6G, against the action of spring 68, to the position shown inFig. l0, thus closing openings 62. When themotor-fan unit is operatedair is drawn through opening 35, and passes as before described to space60. From here the air passes directly into the hose and does not passthrough openings 62 into space E5.

The operation of the dust indicator will now be described.

The dust bag always offers some resistance to the passage of airtherethrough, and hence the pressure existing within inner casing 25 andoutside of the dust bag is lower than the pressure existing within thedust bag.v As dirt accumulates within the bag this adds to theresistance to flow, and hence the pressure drop through the bag is anindication of the amount of dirt contained therein. The low pressureoutside of the bag is communicated through openings 19 to the lower sideof diaphragm 88. As before described, the pressure existing within thebag is communicated to the upper side of the diaphragm. As dirtaccumulates within the bag, this causes an increase in the difference inpressure, and hence there is a greater pressure difference acting on thediaphragm. Inasmuch as the higher pressure exists within the bag andhence on the top of the diaphragm, the diaphragm is caused to movedownwardly against the action of spring 95. This causes the upper end ofrivet 9| to be moved away from part 92 of the indicator member 8|, andweight 81 is able to cause the indicator mem- `lier to rotate slightlyin a clockwise direction. The amount of this rotation is visible throughopening 86 and when it is suillcient the operator knows that the dustbag should be removed and emptied.

In order to remove the dust bag it is only necessary to unfasten clips32 and remove cap 3|. This may be done without standing the cleaner onend inasmuch as theopen end of the bag is in an inclined position andthe dirt contained therein will not fall out when the cap Il is removed.The bag may be withdrawn through opening 20 in the casting I! andemptied. In replacing the bag it is preferable to start the motor-fanunit, and the suction thus produced will draw the bag into place withinthe cleaner. The air flow carries the closed end of the bag to theright, as viewed in Fig. 5, until it strikes the closed end of cage 21.Thereafter, the difference in pressure inside and outside the bag tendsto inflate it to the greatest possible extent and hence tends tostraighten out the bag adjacent to the open end thereof where it issomewhat curved due to ring 28 being in an inclined position. Thistendency to straighten out the bag prevents the formation of folds atthis point, and the folding occurs further back toward the closed end ofthe bag. i

While I have shown one more or less specic embodiment of my invention,it is to be understood that this has been done for purposes ofillustration only and does not constitute a limitation. The scope of theinvention is to be determined by the appended claims viewed in the lightof the prior art.

What I claim is:

i. A casing for a vacuum cleaner including a front member, a lowershell, an upper shell, said front member being formed with an inletopening and an outlet opening, means, for securing said shells togetherand to said front member, a dust bag in said casing, said front memberhaving an inclined wall formed with an opening, means for securing theopen end of said dust bag in said opening, said lower shell havingrunners for movably supporting said casing on a surface, a flexiblehose, and means for connecting an end of said hose to said opening, saidhose being adapted for pulling said casing around on said surface.

2. In a vacuum cleaner, a casing including a lower shell portion and anupper shell portion, a frame member extending upwardly from the side ofsaid lower shell and within said casing, a motorfan unit supported bysaid frame within said casing, and means for securing said upper shellto said frame whereby said shells are held in xed relationship.

3. In a vacuum cleaner, a casing formed with a horizontally extendingspace for a dust bag, a dust bag formed with an open end and having alength greater than the length of said space, and means for securing theopen end of said bag in a position inclined with respect to thelengthwise extent of said space, whereby the axis of the bag is curvedadjacent to said open end.

4. In a vacuum cleaner, a casing arranged to be supported horizontallyon a substantially horizontal surface and formed with an opening in aplane inclined to the horizontal, said opening communicating with aspace within said casing having a horizontal lengthwise extent, a dustbag in said space having a length greater than that of the space, saiddust bag having an open end, and means for removably securing said openend adjacent to said inclined opening in said casing, whereby the axisof the bag is curved adjacent to said open end.

5. A vacuum cleaner including a casing having a horizontal longitudinalextent when normally mounted on a horizontal surface, said casing havingan opening at one end in an inclined plane, a dust bag having an openmouth securable in said opening and normally extending longitudinally ofthe casing, said dust bag being supported in said casing along thebottom so that the center-lineA of the bag is bent adjacent to the mouththereof, a cover for securing said bag at said inclined opening, andsurface contact means on said casing whereby the casing may be pulled inthe line of longitudinal extent.

6. A vacuum cleaner including a casing having a horizontal longitudinalextent when normally mounted on a horizontal surface, said casing havingan opening at one end in an inclined plane, a generally cylindrical dustbag having an open mouth securable in said inclined opening and normallyhaving its axis extending longitudinally of the casing, said dust bagbeing supported in the casing along the bottom so that the axis of thebag is curved adjacent to the mouth thereof, a cover for securing themouth of the bag in the inclined opening, and a hose connectible to saidcover for 'delivering dust-laden air to said bag and for pulling thecasing in the direction of its longitudinal extent.

7. In. a vacuum cleaner, a casing, partition means dividing said casinginto a rst chamber, a

second chamber and a third chamber, said casing being formed/with aninlet opening at one end thereof communicating with one end of saidiirst chamber, and with an outlet opening at the same end communicatingwith one end of said second chamber, the other ends of said ilrst andsecond chambers being in communication, said casing being formed with aplurality of outlet openings communicatingwith said third chamber, saidpartition means being formed with a passage between said second andthird chambers adjacent the first mentioned outlet, means for producingiiow of air through said casing, and valve means for closing said ilrstmentioned outlet and opening said passage and alternatively for openingsaid rst mentioned outlet and closing said passage.

8. In a vacuum cleaner, an elongated casing formed of an upper shellmember and a lower shell member, both of said shells havingsubstantially at portions, means for joiningl said shells in air tightrelation, a motor-fan unit for creating a pressure in said casingdifferent from atmospheric, and reenforcing means in contact with theinterior of said shells serving to stiflen said shells, and particularlyilat portions thereof, against deformation by said pressure differences.f

9. Apparatus as claimed in claim 8 characterized by the fact that saidmotor-fan unit is supported from said reenforcing means.

10. A non-circular, elongated casing for a vac-y uum cleaner of thevtype designed to be pulled horizontally on a supporting surface by ahose including an upper elongated shell, a lower elon gated shell, saidshells having attened portions and being joined together along lines ina plane disposed parallel to said supporting surface, a dust separatingmember within said casing, and means for supporting air-flow producingmeans within said casing, l V

11. In a. vacuum cleaner, an elongated casing, means for supporting saidcasing horizontally on a horizontal surface, said casing including atleast two shells having flattened portions and open ends, said shellsbeing Joined together in air-tight relation along linesin a planedisposed parallel to the lengthwise extent. of saidcasing, an end memberformed with a dust bag opening, means for securing both of said shellsto said end member, a dust bag securable in said dust bag opening, andlmeans for supporting air-flow producing means within said shells.

12. In -a vacuum cleaner, an elongated casin having a substantially fiatportion, a motor fan within and in contact with the interior of saidcasing serving to stiifen said casing, and particularly the flat portionthereof, against deformation diierences.-

by said pressure GUSTAF EINAR LOFGREN.

